1. Field of the Invention
The present invention relates to an information recording medium, such as an optical disk of a high recording density type, which is capable of recording as video information, audio information and the like, at a high density, and which is exemplified by a DVD (Digital Video or Versatile Disk). The present invention also relates to a recording apparatus for recording the information onto the information recording medium, and a reproducing apparatus for reproducing the information from the information recording medium.
2. Description of the Related Art
Conventionally, an LD (Laser Disk) and a CD (Compact Disk) are generally referred to as optical disks, on which video information, audio information, and the like, is recorded.
On the LD, the video information and the audio information are recorded together with time information indicating a time at which each information is to be reproduced with respect to a reproduction start position, which each LD includes at a standard position. Thus, other than a general normal reproduction to reproduce the recorded information in the order of recording, various special reproductions are possible, such as a reproduction to extract and listen to an only desirable portion of recorded music on the disc, a reproduction to listen to the recorded music in a random order and so on, in case of the CD, for example.
However, there is a problem that, according to the above mentioned LD or the like, a so-called interactive and variegated reproduction is not possible in which the audience can have a plurality of selection branches as for the video or audio information to be displayed or outputted and in which the audience can select to watch or listen to.
In particular, in conventional arrangements, it is impossible for a user to choose the language used in the subtitle on the screen (e.g., from subtitles in Japanese and the original language) in the case of watching a foreign movie recorded on a LD or to choose the voices of a song (e.g., from English voices or Japanese Voices) in the case of listening to the music recorded on a CD.
Recently, apart from the above-mentioned conventional CD, it is proposed and developed a DVD which is an optical disc which disc size is identical to CD and which recording capacity is enhanced to be approximately ten times larger than that of CD. Generally, there is employed a function called "parental control" in the DVD system. Parental control is a control method which enables the DVD player to judge information portions which parents do not want to show their kids and automatically execute the choice of the information and the reproduction of the recorded program without those portions. The player is set (user-alterable) a parental level prescribing the information that the player itself can reproduce, and chooses PGCs (ProGram Chain) in consideration of the parental level to reproduce information. With the aid of the function of the parental control, it is possible to record simultaneously-advancing multi-stories on a single disk. However, since the parental levels are different from country to country, it is desired that an identical disk can be reproduced in different ways according to the parental levels which are set differently in various countries.